hey boat,
There is generally a surf running and it churns up the water, but depends when u go, and if the westerly has been blowing warm clean water will come in. For a beginner snorkeler she may be disappointed, probably bitterly disappointed after vidal.
Spearfishing is another story and depends how far u want to walk and the conditions. I suggest u look at google earth and u will see the reefs, some lose in. I would trend toward moving west and find spot close to those reefs. Good cracker both black and white. Actually u could expect any reefys but those being the prize and if u get to the pinnacles you may be lucky to bump into a yellowtail.
this site will give you better understanding of the reefs
http://www.navionics.com/en/webapp
then not far Kenton middle beach has some good diving too. Head out left from the car park. There is some amazing reef there also with everything and u will see some pinnicles about 400m out. If u fit enough to get there i know of yellowtail of over 20kg speared there, big cracker (both) too. But i wouldnt do that one alone and watch there is a west to east current there at times
For your lady i know there is a scuba school in port alfred, also not too far away, they take you out to fountain rocks. I havent done it but apparently a good dive.
Hope this helps, give me a shout if u need any other info